Telephone system



Icz. w. KECKLER TELEPHONE SYSTEM /n l/e/var Char/@S Vl/ Heck/eff I by A# .u MKEEMO@ E iatented Aug. Z8, i923.

strains.

CHARLES XV. KECKLER, OF NETARK, NEW JERSEY, ASSIGNOB '150,NESTERN ELECTRIC COMPANY, INCORPORATED, OFNE/V YORK, N. Y., ACORPGRATON OF ,NEW YORK.

TELEPHONE syrsrnia.

Apriciaton filedv @ctober Q1, 1919. Serial No.1332,265.

To all fui/0m if 'may concern-1.'

l vBe it lnoirn thrt l, Cinxiinns TVV. KncxLnn, a citizen ot the United States, resiuing at Newark, in tile' county oi"`fs,ex, State ci. New useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description. i'

`This invention relates to telephone ex: change systems, and more 'particularly to such systems in which Connections between telephone lines terminating' at manual and automatic exchanges are established by Way of trunk Vcircuits, over which automatic sivitches are controlled from the'manual exchange for effecting connections between the trunk circuits and telephone lines at'theV automatic exchange.

The object ot this 'invention 1s Vthe production of ari-improved system of this character by which theoperators at a manual exchange may control over the trunk circuit, the automatic switches provided at the automaticexchange, for establishing connections between the trunk circuits and the telephone lines. 1 A

In accordance With the various features of this invention, the transmission ofselecting impr; ses over the 'trunk circuit from the manual exchange to the automatic exchange is eillectedby maintaining an impedance element ina bridge across the talking conductors ot the trunk circuit y during the actuation of the impulse sending crevice, and intermittently interrupting this bridge whereby the automatic switches atY the automatic exchange are controlled. A.

Y relay provided in the trunl circuit and controlled over the ring conductor 01"' the enlraged link and trunk circuits and responding to the Vactuation of the impulse sending device connecting key, controls the shortcircuiting ot the impedance element and a relaycontrolledlover the tip talkingconductor of the engaged .link and trunk circuits by the' impulse sending device controls the intermittent interruptionfof the bridge. Preferably, these rela-ys are .associated With the respective talltingconductors only during the time that the impulses are being l transmitted.

F or a more complete understanding of this invention, reference should be made to the `tollou/'ing description considered in connection with the accompanying drawing Jersey, have invented certain new andV short-circuited' Which illustrates one embodiment of the'invention, i I

There is shown inthe drawing a ,telephone .line A terminating atfa manual' exchange, Where it maybe connected With the iinlr circuit BL in any suitable andV Welllniown manner. Thel calling` end ot the link;

circuit B may beconnected Witha trunlrcir-Y cuit C, extending from the manual to the automatic exchange, at which areprovided the usual selector and vconnector switches, tor effecting connection between the trunk circuit and telephonew lines, such as D, ter'- minating at the automaticV exchange. At the automatic exchange, the trunk circuit is multiplied to jack terminals at a toll switchboard at which is located the linkv circuitV E, by means of which connection may be established with the .trunk circuit and signals. at the ina'nual exchange controlled therefrom. The' apparatus shoivnf to the lett of the dotted liner-f1 isflocated at the manual exchange, While that shown to the right ot the dotted line is located at :the automatic exchange. p' The nature'of thisinvention is such-.that it is believed aclear understanding thereof will be obtained from a description of." the operation of systemsv shou'nin "the drawing, and-it will beso described. I i I i y' i The subscriber at thestation on telephone line A having initiated al *call vand the answering end of the 'linlr circuit B" having been associated therewith' in any Well-known' manner, the'operator actuatcs listening keyk 5 connectingthe operatoi"s telephone sety in circuit-so that' the operator may converse Withthe eallingsubscriber to ascertain the number of the line With which connection is desired. Assuming that connection is'desiredwith telephone line D which `terminates at the automat-ic exchange, the operator inserts calling plug 6 ot the link-circuitQB into jack '7 oit the' trunk circuit CJ, ielay `Sthereupon operates over a 'circuit .from battery throughthel Winding ot over a circuit from battery through resisttasas,

relay 8 Vcausestheenergization -ot relay13 over aV circuit from battery through the right-hand contact ot relay 8, winding of relay. 13, left-hand normal contact of relay. 15,

tipv contacts 'of the jack 7 and-.the plug 6,4v

upper normal Contact of key 10, and upper Ynormal contact of ringing key 23 to ground..

Relay 13 in opera-ting bridges r,signal-control relay 16 across the talking conductors of the trunk circuit, whereupon signal-control relay 16 and impulse responsive relay 17 operate over a circuit 'from battery through the left-handl winding or impulse responsev relay 17, Aleft-hand.contact of cutoli" relay 34:, Contact of relay 13, Winding of relay 16, right-hand normal contact cit' relay 15, right-hand contact of cutoff relay 3%, and the right-hand winding ofV impulse response relay 17' to ground. yRelay 16, in operating, removes a short circuit from the high resistance right-hand Winding ot relay 11, and

l causes the energization of relay 15 over a lay 15 to ground.

circuit from battery through the left-hand contact of"`relay 11, winding ot relay 15, alternate contact of relay 16, and the lett.- ha'nd alternate contact of relay 8 to ground. Relay 15, in operating also establishes a locking circuitV` for itself from Ybattery through thelet-hand contact of relay 11, Winding and inner rightliand Contact of re- RelayV 15, in operating, disconnects relay 13 from the tip Ytalking conductor of the trunk circuit, and completes the continuity of the ring talking conductor at its outer left-hand contact. A holdingcircuit for relay 13 is/also estab'- lished, wherebyv the continuity of the bridge including` signal-control relay 16 is maintained. 'Relay 15, in operating, removes the short-circuit from impedance coil 18, vthereby including this impedance coil in series with the Winding of relay 16. Condensers 39 and 40 connected in the talking conductors serve to electrically divide the talking conductors into inner and outer sections to prevent battery from the link circuitB from interfering with apparatus at the automatic exchange and to prevent battery from theV automatic exchange `from interfering With apparatus connected` with theV inner section of thetalking conductors.

The operator, `after inserting the plug 6 into the jack 7,may actuatethe impulse i sending device connecting key 10 to connect the impulse sending device 211 with 'the link circuit B and through the link circuit withv the trunk circuit C; The opening of thev lower normal contact ot thiskey 10. causes the deenergization of relay 11, whereupon relay 15 releases, short-circuiting impedance coil 13 which is bridged across the talking conductors of the trunk circuit. Relay 8 is reconnected with the ringtalking conductorand is'held energized. Relay 13 is also .held energized through the closure of the upper alternatey ycontact of thekey 10 and lthe contact of the impulsesending device. y

YRelay 8 is also reconnected with the y.

lring talkingV conductor by the deenergiza-I tion oi' relaiv 11 and is maintained energized thereover. Relay 13 Which is 1n circintwith the contact of impulse sending device 24Y fellows the operation of this device and is y deenergized and energized upon each opening and closing oli the contact thereof.V

Therefore, during the operationof vthe send` ing device for transmitting the proper num-V ber of selecting impulses, relay 13 opens-and closes a bridge across the talking conductors` or the trunk circuit so that impulse .responsive relay 17l 4ollovvs the actuation 'of the sending device. Impulse response Vrelay 17 controls the usual motor magnets for causing 'the proper functloning'ofthe se-` After the impulses have vbeen transmitted,` the operator may restore the key 10 tenor-V mal position causing thereenergization of relay 11 which disconnects relay 8 from the Yring talking conductor but maintains this relay energized. Relay 15VY is reenergized upon the operation of relay 11 and locks up in the manner before described. Relay 15,

in operating, also reestablishes the continuity ot the ring talking conductor 'of the llO trunk circuit, removes the short circuit of impedance coil 18, and. disconnects the relay 13 from the tip talking conductor of the trunk circuit. energized through contacts of relays'8 and 15 and being energized, maintains the bridge including the' Winding of relay 16 and impedance coil 18. This bridge is of high impedance to talking currents andhas little, it any, Yeffect thereon. By maintaining the impedance coil 18 short circuited during the transmission of the selecting impulses, the signaling range is increased. By providing a non-inductive shunt 28 for relay 16, inductivey disturbances due to the presence ot relay 16 in the circuit While the impulses are being transmitted,V are prevented.

f The subscriber may be vsignaled in any Relay 13 is maintainedV Cal usual and well-known manner, and thesubsequent removal of the receiver from the switclihook at the station of the telephone line D completes the talking circuit between telephone lines A and D. At the conclusion or the conversation the receivers are re stored to their respective switchhooks. vThe restoration of the receiver to the switchhook at the station of telephone line A causes thev operation of the usual disconnect signal Vat the manual exchange, whereupon theoperator may withdraw the plug 6 from the ack 7 sov that all apparatus of the link and trunk circuits is restored -to normal position` Should the toll operator at the automatic exchange desire to establish'connection with a telephone line terminating at the manual exchange, plug 35 oi the toll link circuit E is inserted in jack 36 and ringing key 37 lis actuated, whereupon, relay 32 and slow-release cutoff relay 34 operate. Relay 32 causes supervisory lamp 33 to be lighted while cutoii' relay 34 disconnects impulse response relay 17 from the talking conductors.

' lCutoff relay 34 is made slow in releasingl to prevent reconnection otv impulse response relay 17 with the talking conductors due to any momentary withdrawal ot the plug 35 from the. jack 36. The actuation of ringing key 37 causes the energizaticn of ring-up relay 12 over a circuit vfrom a source oit ring` ing ciirr'ent-38, through-the lower alternate contact of the ringing key 37, ring contacts or" the plug 35 and the jack 36,' condenser 39, normal contact and winding of relay 12 and the normal contact of relay 8 to ground.

Relay v19. in operating establishes a locking` circuit for itself from battery through ns right-hand alternate 'Contact and winding, and the normal Contact of relay 8 to ground.

' Relay 12, in operating, also causes the lamp 41 to be lighted to furnish a signal to the operator at the manual exchange.

The operator at the manual exchange. upon observing the lighted condition of the lamp 41, niay insert the plug 6 of the link circuit B into the jack 7 of the trunk circuit C.

Relay 8 thereupon operates overthe circuit hereinbetore traced, and opens the locking circuit of relay 12l which thereupon releases to extinguish the lamp 41. The energization of relay 8 also causes the energization of relays 11 and 13. The energization of relay 13 causes the operation et supervisory relay 43 and signal-control relay 16 over a circuit from battery through the right-hand winding of supervisory relay 43, lower norv` mal Contact of ringing key 37, ring contacts or" the plug 35 and the tiack 36,.contact of relay 13, winding oin relay 16, right-hand normal contact of relay 15 or the impedanceV coil 1S (depending upon the condition of relay 15), tipcontacts .of the jack36 and the plug the iipper normalV contact ot i ringing key 37 and the lett-hand winding oi' relay 43 to ground.v Supervisory lamp4 is thereby extinguished. The operation of re,-

circuit with the two windings oft relay '11, but the right-hand winding oi relay 11 is of;

such' high resistance that the lamp lwillno't be lig'ghte'd.l Theoperatorat they manual ex change may actuate thelistening key 5 to connectthe operators telephone set withthe Vtalkingconductors so that thefoperators may converse, listening' key 42 at the Itoll operators position having previously .been actuated to connect the toll operators telephone setin circuitaftei the extinguishnient of the lamp 33 whichis a signal to the toll op;- eratorv that the/manual operator has answered. VAfter receiving the proper instruetions as to the line with which connection is desired, the operators may restorethe listen-A` ing keys to normal position and theoperator at: the manual exchange may, ini any well-l known manner, establishA connection with the desired line.

After such a connection has been established as described in the precedingparagraph, the toll operator may desireto recall the operator at'the manual exchangeand this may he done by repeatedlyand momentarily withdrawing the plug v351mm the jack 36. U pon each withdrawal oit this plug, relay 16jdeenergizes to close itsnorrnal con tact which establishes a shortV circuit for the high resistanceright-hand winding of relay 11. rlhe resistance of the .circuit including the lamp 30 is thereby reduced toA such an extent that the lamp` is lighted. i Upon ico each insertion of the plug'35 into the vjack'.

36,Yhoweveryrelay. 16 reenergizesto remove theshort circuit ofthe highrresistance right# hand'winding of relay 11 so'that the lamp is extinguished. f, Therefore, only duringr each withdrawal of the plug is the lamp 30,

lighted. In this manner, the lamp is lighted intermittently during such continued with# drawals of the plug and fiirnishesa signal to the operator at the manual exchange that the toll operator is recalling.' After repeatedly removing the plug vin this manner the toll operator may 4let the plug rest in thejack and,' of course, the relay 16 will remain energized. VSincev ciitoil relay 34 is slow in releasing,.impulsel response relay 17 is not aeeted bysuch continued withdrawal of the plug 35. The operator at the manual exchange, upon obserying the flashing or in-l termittent lighting or"Y the lamp 3 0, may' actuate the listening key 5to-connect the telephone setl incircuit with that oi' the toll operator which has beenjpreyiously yconA cri;

icl

nected with the talking conductors'through the actuation ot the listening ker-V42. instead Oirepeatedly Withdravvinglthe plugrom the jack 'to recall the operator at the i manual switchboard, the operator at the toll Vthe manual switchboard u'illbe `flashed in Y ductors of the link-circuit and inner section,

the same manner :is before described.A

Y rliliat is claimed is: Y i

l. in a telephone *exchange system, in combination, a trunk circuit comprising a pair'ot talking conductors, inductive means electrically dividing the talking conductors into inner and outer sections, a. bridge for the outer section, an impulse sending de#Y vice, anA impulse response relay, a link circuit, a' primary relay energized over one of the talking conductors ot the inner section upon the' connection ot the link circuit with the trunk circuit, a secondary relay ior intermittently opening the bridge to control the impulse response relay, and an energizing circuit for the secondary relay controlled bythe impulse sending device and 'the primary relay.

2. ln a telephone exchange system, in combination, a trunk circuit comprising a pair oftalking conductors, inductive means electrically dividing the talking conductors into inner and outer sections, a bridge for the lout-er section, an impulse sending device, an impulse response relay, a link circuit connected With the trunk circuit, means for` connecting the impulse Vsending device Vwith the link circuit, a primary relay energized over one of the engaged talking conand a secondary relay controlled over the other engaged talking conductor of the link circuitV and inner section by the impulse sending device and the primary relay for rintermittently opening the bridge to control the impulse response relay.

3. In a telephoneV exchange system, in combination, a trunk circuit comprising a pair .of talking conductors, inductive means electrically dividing the talking conductors into inner and outer sections, a/bridge for the outer section, an impulse sending device, an impulse response relay, means for connecting the impulse sending device with the trunk circuit, a primary relay energized over one vcil the talking conducters of the inner section, a` secondary relay controlled over the othertalking conductor of the inner section by the impulse sending device and the primary relay for internfiittently opening the bridge to control the'impulse vresponse relay, an impedance element, and

ino'

into inner and outer. sections, a bridge for the outer section, animpulse sending-des vice,lan impulse response. relay, means 'torconnect-n0- Jrhe impulsesending devieefwith -AA u c thetru-nk circuit,va primary relay energized over one oithe tallnng Vconductors ofV the inner section., a secondary relay controlled over the other engaged 'talking conductorY of the inner section by the .impulse sending device and the primary relay for interinit tently opening the bridge to control the impulse response relay, and means responsive to the disconnect-ion ot the impulse sending device from the trunk circuit for 'disconnectg the secondary relay from the talking conductors.

5. ln a telephone exchange system, in

combination, aitrunk circuit comprisingra pair of talking conductors, inductive means:

electrically dividing the talking conductors Vinto inner and outer sections, a bridgefor the outer section, an impulsesending device. an impulse response relay, means for connecting; the impulse sending device with the trunk circuit, a primary relay energized over one of the talking conductorsoii Vthe innerv section, a secondary relay controlled over the other engaged talking conductorof the inner section by the impulse 'sending device and the primary rela-y for intermittently opening tbebridge to control' the impulse response'rel to the disconnection oi the impulse sending device from the trunk circuit tor disconand ine-ans responsive necting therprimary relay from the talking conductors.

6'. ln a, telephone exchange system, in combination, a truuk circuit` co arising 'a pair oi: talking` conductors, inductive meansel'ectrieally dividing the talking conductors into inner and outer sections, a bric ge for the outer section, an in pulse scndingdevice. an impulse response relay, means for connecting .ne impulse sending device with the trunk circuit, a primary relay energized over one ot the talking conductors of the inner section, a secondary relay controlled over the other talking conductor oit theinner section by the impulse. sending device and the primary relayfor intermittently opening the bridge to Vcontrol the impulse response relay, and means responsive tothe disconnection of the impulse sending device from they trunk circuit ttor disconnecting the primary and secondary relays romthe talking conductors. l

7.y ln atelephone exchange system, in comof talking; conductors, ir

bination a. trunk circuit com risin a air trunk circuit, a priinary relay energized over one et the talking conductors et tbe inner section,a secondary relay controlled over the other talking conductor tbe inner section by the impulse sending device and the priinarv relav for intermittently opening tliev bringe to control the impulse response relay, impedance element, and means responsive to tbe disconnection orn the impul^^ sending device from the trunk circuit n -ipe-dance element in vicludin o tbe the bridge and Yfor di connecting the priys from the talking mary and secondary rel conductors. l

S. ln a telephone exchange system, in combination, a trunk circuit ,f m

ctiv means electrically dividinga the talkin@ n conductors into inner and outer vsectionsabridge. :tor tbe outer section, an impulse sendino' device, an impulse response relay, means :t connectin e the impulse sending device ivitli the trunk circuit, a primary relay energized over one ot tbe talking` conductors ot tbe inner section, a secondary relay controlled Vover the other talking' conductor of the inner section by the impulse sending` device and the primary relay for intermittently opening the bride-e to control the impulseresponse relay, a relay in tbe bridge controlled over the outer section et the trunk circuit, and a relay controlled by tbe bridged relay and responsive to the disconnection ot the impulse sending' device 'from tlie trunk circuit for disconnecting the primary and secondary relays from tbe talking conductors.

. 9. In a telephone exchange system, in com- Y bination, a trunk circuit comprising a pair of talkingconductors, inductive means electrically dividing the talking conductors into inner and outer sections, a bridge for the outer section, an impulse sending device, an

.impulse response relay, means for connecting the impulsel sendingdevice with the; ltrunk circuit, a primary relay energize-d over one i theV talking conducto-rsof the inner-section, a secondary relay controlled over the otliertalking conductor oi the inner section by the impulse sending; device and the primary relay for intermittently opening'tlie bridge to control thev impulse response relay, and a relay responsive to the-disconnection olf' tlie'iinpulse sending device -irom the trunk circuit tor disconnecting rthe primary and secondary relays from the talking conductors andl for maintaining tliese relays energized condition; l0. 1n a telep-honeexcliange systein,in

combination a trunk circuit com :irisinev a pair ot talking conductors, Vinductivemeans electrically dividing tlie talking lconducto-rs into inner and Youter sections, said inner sectionliaving aV normally open contact` in said talking conducto-rs, a bridge for the outer section, an impulse sending device, an impulse responsive relay, means for connecting tlie impulse sending1 device With the trunk circuit, a primary relay energized over one of the talking conductors of the. inner section, a secondary relay controlled over tbe other talking` conductor ofthe inner section by the impulse sending' device and the primary relay tor intermittently opening tbe bridge to control the impulse response relay, and a relay responsiveto the disconnectionv of the impulse sending device from the trunk circuit for disconnectingthe primary and secondary relays from the talking conductors and tor closing the normally open Contact.V

In Witness Whereoi hereunto subscribe my name this 3rd day oi. October A. D., 1919. Y CHARLES W. KECKLER. 

